扩展表单。选择多个而不丢失值

我有一个模型表单,我正在为它编写一个自定义小部件,以替换多对多表单。使用jQuery FCBKcomplete小部件选择多个字段。虽然替换“multiselect”元素可以正常工作,但它不再为“multiselect”提取选项。

这是我的小部件:

class FCBKcompleteWidget(forms.SelectMultiple):
    def _media(self):
        return forms.Media(js=(reverse('appstatic',
                                       args=['js/jquery.fcbkcomplete.min.js']),
                               reverse('appstatic',
                                       args=['js/init-fcbkcomplete.js'])),
                           css={'all': (reverse('appstatic',
                                                args=['css/jquery.fcbkcomplete'
                                                      '.css']),)})

    media = property(_media)

这是我的表格:

class BlogForm(forms.ModelForm):
    class Meta(object):
        model = models.Blog
        exclude = ('slug',)

    def __init__(self, *args, **kwargs):
        super(BlogForm, self).__init__(*args, **kwargs)
        self.fields['description'].widget = TinyMCEWidget()

        fcbkcomplete_fields = ['categories', 'admins', 'editors']

        for field in fcbkcomplete_fields:
            self.fields[field].widget = FCBKcompleteWidget()

以下是我的模型:

class Category(models.Model):
    """A blog category"""

    title = models.CharField(max_length=128)
    slug = models.SlugField()

    class Meta(object):
        verbose_name_plural = u'Categories'

    def __unicode__(self):
        return self.title

    @models.permalink
    def get_absolute_url(self):
        return ('category', (), {'slug': self.slug})


class Blog(models.Model):
    """A blog"""

    title = models.CharField(max_length=128)
    slug = models.SlugField(unique=True)
    description = models.TextField()
    categories = models.ManyToManyField(Category, related_name='blogs')
    shared = models.BooleanField()
    admins = models.ManyToManyField(User, related_name='blog_admins')
    editors = models.ManyToManyField(User, related_name='blog_editors')

    def __unicode__(self):
        return self.title

    @models.permalink
    def get_absolute_url(self):
        return ('blog', (), {'slug': self.slug})

以下是生成的HTML:

<div class="field">
  <label for="name">Categories</label>
  <select multiple="multiple" name="categories" id="id_categories">
  </select>
  <div class="help-text">trimmed for readability</div>
</div>
<div class="field">
  <label for="name">Admins</label>
  <select multiple="multiple" name="admins" id="id_admins">
  </select>
  <div class="help-text">trimmed for readability</div>
</div>
<div class="field">
  <label for="name">Editors</label>
  <select multiple="multiple" name="editors" id="id_editors">
  </select>
  <div class="help-text">trimmed for readability</div>
</div>

正如您所看到的,没有一个选项可以将其添加到multiselect元素中。以下是我不使用自定义小部件替换小部件时生成的HTML:

<div class="field">
  <label for="name">Categories</label>
  <select multiple="multiple" name="categories" id="id_categories">
    <option value="1" selected="selected">Good Stuff</option>
  </select>
  <div class="help-text">trimmed</div>
</div>
<div class="field">
  <label for="name">Admins</label>
  <select multiple="multiple" name="admins" id="id_admins">
    <option value="2" selected="selected">username</option>
    <option value="3">some username</option>
    <option value="4">another username</option>
  </select>
  <div class="help-text">trimmed</div>
</div>
<div class="field">
  <label for="name">Editors</label>
  <select multiple="multiple" name="editors" id="id_editors">
    <option value="2" selected="selected">username</option>
    <option value="3">some username</option>
    <option value="4">another username</option>
  </select>
  <div class="help-text">trimmed</div>
</div>

有没有人对为什么这些选项不能通过小部件更换过程提出任何建议?任何帮助都将不胜感激。